Why Are Fusion Dimensions 10X greater on imported .STL files?

[lorne01]

I tried out Fusion 360 this evening.  I found it odd that every .stl i imported had the dimensions wrong.  I verified with Sketchup, and sketch up has the dimensions right.  I have figured out that the dimensions are out by a factor of 10.  

Is there some setting or something that needs to be changed to get the proper dimensions?  

The picture attached is of a ruler that is verified in Sketchup to be 10mm (length of the green line, but in Fusion it is 97MM.  Does this mean all my prints will be 10X bigger than they should be and i will have to mentally adjust for the error?  

I would appreciate if you have any insight.  

[Anonymous]

Hello,

Here an example when reading the STEP file from Fusion 360 into the designer software of a CNC bending machine called bysoft 6. With this simple software it is not possible to adapt the unit; it is reading the file only in mm and inches (see image: it is indicating 79.5, where it should be 795mm). Reading a step file from solidworks does not gives this problem. I agree that there should be an option in the CNC program to adapt, but there is not. But also, as fusion is the drawing program, there should also be an option in here too. It is confusing that solidworks is using mm for example and fusion 360 is using cm..

Regards

[Phil.E]

Thanks, great example.

Regards,

[MontyFlange]

I can't fix it 😞 every STL I import is to huge to work with now.

[Phil.E]

@MontyFlange

Sorry to hear you are still having trouble with it.

This is probably the best possible thread on this forum to explain what is going on with STL import and how to get the right size. Did you try the solutions listed here?

To sum it up for you:

1. STL is unitless, meaning centimeter, inch, millimeter units are not handled by the STL file.

2. Because of this, the exporting software and importing software have to agree about what "one unit" of distance means. Is it an inch or mm? Both ends have to agree.

3. STL that is imported via "upload" will be considered "centimeter". This is because the upload function does not currently have the ability to pick units when you upload.

4. Because of this, you are better off doing the workflow below.

STL import with correct units workflow:

1. New design.

2. Insert menu > Insert Mesh

3. Pick the units for the STL file you wish to insert.

4. OK.

Here is what the insert dialog looks like:

Please let me know if this works for you.

 If this is not working for you we need to see what is going wrong on your end. I'm happy to help you get the units right on your STL imports!

Thanks,

[Anonymous]

Thanks Phil for your clear explanation.... i've sorted the importing mesh issue now BUT since I imported the mesh within Model workspace, I can't seem to access MESH workspace when I followed this workflow.

Please help...

[Phil.E]

@Anonymous

Welcome to the Fusion forum!

The mesh workspace is an environment you create as a node in your timeline. This is done from Create > Create Mesh. 

So if you wish to simply insert a mesh into a model space as a reference, use the instructions I posted above.

If you wish to use the mesh workspace, first Create Mesh, and then use Create > Insert mesh while in the mesh workspace.

Please let us know if you have more questions.

Thanks,

[Anonymous]

Thanks for your prompt reply Phil! 😉

[Phil.E]

@Anonymous

I forgot to mention. If you are using the Mesh Workspace preview (found on the preview tab of Preferences) all meshes are equal in Model space - there are no special cases. So really, all you need to do, no matter where or how the Mesh is inserted,  is right click on the body and pick Edit. This will launch the Mesh Workspace tools.

Thanks,

[MontyFlange]

As of today every time I open up one of my models they are a lot bigger. the decimal point has sifted one to the right so a 34mm model is now 340.0mm . These where made in F360 but the last version. So they should be fine in this version.

[Phil.E]

@MontyFlange

Something must be going on here for you that isn't for other customers.

For one, Fusion does not re-translate your data when you open it. And secondly, I don't see other reports of this and you aren't the only one with STL files.

Typically this is seen when people upload mesh to A360 and then open it. The A360 translators handle the unitless STL as centimeter because there is no way to pick units when you upload it. This is a problem and I don't think it's been fixed. However, it is easily overcome by using Insert Mesh and picking units.

So just so we are clear about what you're seeing, can you describe your workflow? What steps do you take that show you this problem? 

Thanks,

[lorne01]

Phil,

I’ve tried the import function on several users computers and it performs exactly the same way. By looking at the responses on the forum, it appears there are others worldwide to experience the same problem.

It does appear that the issue confuses centimetres with millimetres thereby making the drawing 10 times larger. Every attempt that I have made to change the settings does not result in the desired expectations.

The solution that I have adopted involves loading the drawing, scaling the drawing to 0.1 and saving it. It’s an extra step, but reliable. Is there a way to write a macro so that the scaling can be done with a single click?

Best regards,

Lorne

[Phil.E]

@lorne01

I'm a bit stumped because this thread explains the differences between uploading mesh for translation and inserting mesh into a model. The end result is the same thing: a Fusion file with a mesh in it.

So I'm wondering what you are doing in the "insert" part of the workflow, not the workaround you describe. How does your workflow begin?

For instance, here is a video showing the import workflow and the use of units selection: (for some reason measure is not snapping to points on the mesh, so the measures are approximate according to my picks, not the actual snap points on the corners)

[MontyFlange]

It can't be anything to do with importing as its happening with models I've made in F360 as well as STLs I've imported

[Phil.E]

It sounds like you can repeat this with new data. That is the only way I can diagnose it. When I try new data, I get good results. So I'm not sure what you are doing to achieve this problem.

Can you post a file and/or video to show this? I'm still not clear about your workflow, so include numbered steps to repeat it.

Thanks,

[MontyFlange]

I'm not 100% sure what you mean/want. I'm not a big CAD user so some terminology escapes me. But here's what I mean

When I made this in the older version these holes where 8mm . Now opening then with the new version they are 18.8mm

Other parts are 100% to large.

I'll export this as a new STL and then re import it to the collection and open it and see what happens

[MontyFlange]

It's 60.2mm now. This is the imported STL

[HughesTooling]

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@MontyFlange wrote:

I'm not 100% sure what you mean/want. I'm not a big CAD user so some terminology escapes me. But here's what I mean

When I made this in the older version these holes where 8mm . Now opening then with the new version they are 18.8mm

Other parts are 100% to large.

I'll export this as a new STL and then re import it to the collection and open it and see what happens

---

Your image shows the edge length not the diameter, it looks like the hole is through a cylinder so the measure tool is probably not going to give a diameter. If there's a cylindrical surface it might work.

18.8mm for the edge doesn't seem right for an 8mm hole though, 18.8 is more like a 6mm hole. You should be able to double check by editing the hole feature in the timeline.

Mark

[HughesTooling]

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@MontyFlange wrote:

It's 60.2mm now. This is the imported STL

---

How are you importing? Are you using the data panel and upload or are you using Insert Mesh on the Insert menu. Insert Mesh will let you set the units, I think upload in the data panel will assume your model in in CM so it will be 10x too big.

Mark

[MontyFlange]

I'm using the panel on the left. You can see the STL has been added there. Then I click on it and OPEN.

[MontyFlange]

OK Imported the correct size part using the mesh option. It was the right size (6mm holes) . Saved to to my work folder on the left. Re opened it and now the holes are 8.288 They where 6mm in the mesh import. So something is happening when I save them to my works folder